In a conventional arrangement of connectors for stackable computer boards, a common bus from a computer motherboard is routed directly through each of the stacked board connectors. Each daughter board contains a decoder programmed to recognise the occurrence on the bus of a unique address or a unique range of addresses assigned to the particular board. The motherboard can access any one of the daughter boards through the connectors by supplying an appropriate address to the bus.
This arrangement is inconvenient in that each daughter board must be different from the other daughter boards, being programmed to recognise different addresses from those recognised by the other boards. If this is not done, several daughter boards may respond to the same address, causing a conflict of data on the bus. Thus although the daughter boards may of the same type and performing the same operations, they must be different to accommodate different unique addressing.